Aqueous suspension concentrate comprising an acid salt of dodecylguanidine

ABSTRACT

The invention concerns a suspension concentrate comprising, expressed by weight based on the total weight of the composition: a) 40 to 80% particles of dodecylguanidine or an acid salt of dodecylguanidine of the structure (1), wherein X represents an acid residue of a monocarboxylic, dicarboxylic or a mineral acid, b) 0 to 10% of an anti-freeze compound, c) 1 to 10% of a wetting agent and/or d) a dispersing agent, e) 0 to 5% of an antifoaming agent, f) remainder water characterized in that, the median diameter of the particles (d 50 ) is at least 7 μm and below 40 μm; and its use for the treatment of a fungicidal disease on crops or ornamental plants.

TECHNICAL FIELD

The invention pertains to the technical field of formulations of activeingredients for application in crop protection. In particular, theinvention pertains to an aqueous suspension concentrate comprisingdodecylguanidine, in particular dodecylguanidine acetate, commonly knownas dodine. The invention also relates to uses of the composition inagriculture.

BACKGROUND

Crop protection compositions can in principle be formulated in differentways, the properties of the active ingredients and the nature of theformulation possibly posing problems in terms of the ease ofpreparation, stability, ease of application, and activity of theformulations. Moreover, for reasons of economics and ecology, certainformulations are more advantageous than others.

Generally there is a need for highly concentrated formulations of activeingredients, since such formulations are associated with a number ofadvantages. For example, the cost and complexity of packaging requiredis less than for low-concentration formulations. Correspondingly thereis a resultant reduction in the cost and complexity of production,transport, and storage, and additionally the operations of preparing thespray liquids that are used in agriculture, for example, are simplifiedas a result of the handling of low-volume containers of crop protectioncompositions, such as during the operations of dispensing and ofstir-mixing, for example.

Liquid formulations have the advantage over powder formulations thatupon the reconstitution of a spray liquid, typically by adding water,they do not produce dust. Preferred liquid formulations, at they areconcentrated, are suspension concentrates. A suspension concentrate isdefined as a suspension of solid particulate active ingredients in aliquid intended for dilution with water before use. In spite of theirease of use, they are not as concentrated as e.g. powders. The amount ofliquid phase comprised in the formulation, such oil or water, istypically more than half.

Product development has targeted to obtain fungicidal suspensionconcentrates comprising as much active ingredient as possible. However,the degree of concentration is limited by the requirement to obtain astable product, that is wherein the solid particulates do not settle andwhich can be stored over extended periods of time.

Efforts have concentrated on the reduction of the particle size of theactive ingredient. An increased surface area obtained thereby is oftencorrelated with a higher chemical activity. Formulators have introducedsurfactants into suspension concentrates to improve wetting propertiesto keep the active ingredient particles dispersed in the liquid phase.

Dodecylguanidine acetate, known as dodine, is a fungicide recommendedfor the control of a number of major fungal diseases of crops. Dodine iscurrently formulated as wettable powders, suspension concentrates andwettable granules. It is a slightly yellow fine powder with lowsolubility in water, in particular 0.63 g/I at 25° C., and organicsolvents. It is used against almond scab; apple and pear scab; bananasigatoka; cherry leaf spot; olive leaf spot; peach bacterial spot andleaf curl; peanut early and late leaf spot; pecan scab, liver spot,brown and downy leaf spot, leaf blotch and downy mildew; and walnutanthracnose.

In spite of the importance of these active ingredients, developments inthe area of suspension concentrates comprising dodecylguanidine, or asalt, or ester thereof, have been limited. Stable suspensionconcentrates of dodecylguanidine acetate typically comprise 400 g activeingredient per liter. This is disadvantageous as transport of productsis costly. This is certainly the case where most of the product iswater. In order to reduce the environmental impact of such formulationit would be advantageous to be able to produce formulations that aremuch more concentrated. It is also of interest to have formulations thathave an improved toxicological profile, yet are sufficiently effectiveagainst the targeted pest.

US 2008/274154 teaches that suspension concentrates containing acrylicgraft copolymer surfactant and an ionic alkoxylated polyarylphenolphosphate ester surfactant are stable over time at high concentrationsof active materials.

US 2009/325808 describes highly concentrated suspension of slightlywater soluble pesticides that are protected from Ostwald ripening by theuse of polymeric surfactants. Also EP 0 007 731 discloses that highlyconcentrated suspensions of agrochemical active ingredients may beobtained using polymeric surfactants.

WO 2009/082939 describes that very concentrated suspensions offungicides may be obtained by stabilizing an agrochemical activeingredient with one non-ionic dispersing agent and one anionicdispersing agent. Dodine is one of the fungicides that can be formulatedin this way.

The above mentioned disclosures relate to anionic surfactants. This typeof surfactant is not compatible with dodine.

EP 0 388 239 discloses the use of so-called structured surfactants forthe preparation of highly concentrated suspensions of agrochemical orbiocidal active ingredients.

None of these disclosures describes suspension concentrates ofdodecylguanidine, or its salts, having a concentration above 40%.

There remains a need in the art for improved fungicidal suspensionconcentrates comprising dodecyl guanidine, or a salt, or ester thereof.

The present invention aims to resolve at least some of the problemsmentioned above. The invention thereto aims to provide a moreconcentrated formulation than could be achieved thus far. The fungicidalsuspension concentrate should be stable upon prolonged periods ofstorage. It should be economical. The ecological profile should beconsidered. The efficacy for the treatment of fungicidal diseases onagricultural crops should be maintained or improved.

SUMMARY OF THE INVENTION

The present invention provides an aqueous suspension concentrate, aspresented by claim 1, comprising active ingredient in the form ofparticles, characterized in that the median diameter of the particles(d₅₀) is at least 7 μm and below 40 μm.

By the term “aqueous” as used herein, is meant that the solvent used inthe composition is mainly water. Hence, “aqueous” and “water-based” maybe considered synonyms. Water-based formulations generally have theadvantage that they require little or no organic solvent fraction.

By the term “active” as used herein, is meant an ingredient that ischemically active and/or biologically active in origin. By the term“active ingredient” as used herein, is meant dodecylguanidine or a salt,or ester thereof. In this regard an “active” ingredient can be a singleingredient or a combination of ingredients; and the meaning of the term“active” shall be understood to include but not be limited tododecylguanidine or a salt, or ester thereof.

Particle size is typically defined as a log-normal distribution with amedian diameter or d₅₀—that is 50% of the particles measured are lessthan the median value and 50% are greater than the median value. Theterm “particle size distribution” as used herein refers to the relativepercentages by weight or volume of each of the different size fractionsof a particulate matter. The term “median particle size”, “mediandiameter of particles”, “d₅₀”, as used herein refers to the median or50% quantile of a particle size distribution. The term “d₅₀” hencedefines a size where 50 volume percent of the particles have sizes lessthan the value given.

The particle size distributions for the present application can bemeasured using laser light diffraction equipment, such as are sold byMalvern Instruments Ltd., Malvern, Worcestershire, United Kingdom. Othertypes of equipment are also suitable for particle size distributiondeterminations.

Suspension concentrates of dodecylguanidine or a salt, or ester thereof,as known to a person skilled in the art, typically have a medianparticle diameter below 5 μm, typically around 3 μm.

The inventors have found to their surprise that the increase of themedian particle diameter, allowed the preparation of highly concentratedsuspension concentrates. These provide an economical advantage assavings can be made on transportation costs. The compositions providedby the invention are stable over prolonged periods of time and areeasy-to-use.

In a second aspect, the present invention provides the use of acomposition according to an embodiment of the invention for thetreatment of a fungicidal disease on crops or ornamental plants.

By the term “fungicidal disease” as used herein, is meant a diseasecaused by a fungus. By the term “fungicide” as used herein, is meant anytoxin used to kill or inhibit growth of fungi. The present invention inparticular relates to fungicides targeting fungi that cause economicdamage to crops or ornamental plants.

Particularly targeted “fungicidal diseases” in the present invention arealmond scab; apple and pear scab; banana sigatoka; cherry leaf spot;peach bacterial spot and leaf curl; olive leaf spot; peanut early andlate leaf spot; pecan scab, liver spot, brown and downy leaf spot, leafblotch and downy mildew; and walnut anthracnose.

By the term “crops” or “crop plants” as used herein, is meant any kindof agricultural crop, including but not limited to cereals, rice,legumes, cotton, tobacco, vegetables and fruit plants. Preferred arehigh value crops like fruit plants, ornamental crops and nuts.

Fruit plants include, for example, fruits from the Rosacea family, likeapple, pear, and quince; stone fruits, like apricot, cherry, plum andpeach; berries, specifically bramble fruits, like blackberry, raspberry,loganberry and thimbleberry, true berries, like blueberry and cranberry,other berries, like gooseberry and mulberry; accessory fruits, likestrawberry; fruits from the Cucurbitacea family, like gourds, includingsquash and pumpkin; melons and watermelons; citrus and other subtropicalfruits, like lemon, lime, grapefruit, mandarine, clementine, tangerine,orange, avocado, guave, kumquat, logan, lychee and passion fruit; dates,figs, grapes, olives and pomegranate; and tropical fruits, like banana,coconut, durian, eggfruit, mango, mangosteen, papaya, pineapple andtamarind.

Preferred fruit plants are apple, banana, cherry, olive, peach and pear.

Ornamental crops include, but are not limited to, aster, azalea,begonia, boxwood, cacti, caladium, calla, calendula, carnation,chrysanthemum, coleus, columbine, dahlia, daisy, daylily, delphinium,dianthus, Easter lily, fern, ficus, foxglove, fuchsia, gardenia,geranium, gerbera, gladioli, hibiscus, impatiens, iris, ivy, marigold,nasturtium, pansy, peony, petunia, phlox, pinks, poinsettia, rosemary,rose, rubberplant, salvia, sedum, snapdragon, verbena, vinca, wanderingjew and zinnia.

Preferred ornamental crops are fern and rose.

Nuts include almond, Brazil nut, butternut, cashew, chestnut, macadamia,pecan, peanut, pistachio and walnut. Preferred nuts are almond, peanut,pecan nut and walnut.

Compositions provided by the invention are at least as effective asprior art compositions when used in comparable dose rates per hectare.In particular, the efficacy of compositions provided by the inventionfor the treatment of fungicidal diseases on agricultural crops,particularly apple scab, is maintained or improved compared tosuspension concentrates comprising 400 g/l of dodecylguanidine or asalt, or ester thereof. This was unexpected as it was believed thatefficacy would decrease with an increased particle size, due to adecreased surface contact.

DESCRIPTION OF FIGURES

FIG. 1 depicts a typical particle size distribution of a Dodine 544 g/lSC solution according to an embodiment of the invention.

FIG. 2 provides a graphical representation of formulations wherein anaverage particle size is plotted against the viscosity of theformulation obtained.

FIG. 3 depicts the particle size distribution of the Dodine 544 g/l SCformulation of Experiment 5, shortly after its preparation.

FIG. 4 depicts the particle size distribution of the Dodine 544 g/l SCformulation of Experiment 5, after storage for one year at 20° C.+/−2°C.

FIG. 5 depicts the viscosity of several Dodine 600 SC formulations withvarying d50 particle size.

DETAILED DESCRIPTION OF THE INVENTION

The present invention concerns an improved aqueous suspensionconcentrate, and uses of the suspension concentrate.

Unless otherwise defined, all terms used in disclosing the invention,including technical and scientific terms, have the meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs. By means of further guidance, term definitions are included tobetter appreciate the teaching of the present invention.

As used herein, the following terms have the following meanings:

“A”, “an”, and “the” as used herein refers to both singular and pluralreferents unless the context clearly dictates otherwise. By way ofexample, “a compartment” refers to one or more than one compartment.

“About” as used herein referring to a measurable value such as aparameter, an amount, a temporal duration, and the like, is meant toencompass variations of +/−20% or less, preferably +/−10% or less, morepreferably +/−5% or less, even more preferably +/−1% or less, and stillmore preferably +/−0.1% or less of and from the specified value, in sofar such variations are appropriate to perform in the disclosedinvention. However, it is to be understood that the value to which themodifier “about” refers is itself also specifically disclosed.

“Comprise,” “comprising,” and “comprises” and “comprised of” as usedherein are synonymous with “include”, “including”, “includes” or“contain”, “containing”, “contains” and are inclusive or open-endedterms that specifies the presence of what follows e.g. component and donot exclude or preclude the presence of additional, non-recitedcomponents, features, element, members, steps, known in the art ordisclosed therein.

The recitation of numerical ranges by endpoints includes all numbers andfractions subsumed within that range, as well as the recited endpoints.

In a first aspect, the invention provides an aqueous suspensionconcentrate with a composition comprising, expressed by weight based onthe total weight of the composition:

-   -   a) 40 to 80%, preferably 40 to 70%, particles of        dodecylguanidine, a salt or ester thereof;    -   b) 0 to 10% of an anti-freeze compound,    -   c) 1 to 10% of a wetting agent and/or d) a dispersing agent,    -   e) 0 to 5% of an antifoaming agent,    -   f) remainder water        characterized in that, the median diameter of the particles        (d₅₀) is at least 7 μm and below 40 μm.

The upper limit of 40 μm is dictated by a spray nozzle as there is arisk of blocking them when too many particles over 40 μm are present.Between 7 μm and 40 μm the suspension concentrate has an improvedviscosity, below 1500 cPS, which is more workable and allows an increasein the active ingredient content of the formulation.

In a preferred embodiment, d₅₀ is below 20 μm. Preferably d₅₀ is 7-20μm, more preferably d₅₀ is 7-15 μm, most preferably d₅₀ is 7-10 μm.Within this range the SC-formulation, even if highly concentrated,remains stable upon prolonged storage.

The term “aqueous suspension concentrate” refers to suspensionconcentrates based on water.

The expression “% by weight” (weight percent), here and throughout thedescription unless otherwise defined, refers to the relative weight ofthe respective component based on the overall weight of the formulation.

The fraction of water in the suspension concentrates of the inventionmay be in general 20%-60% by weight, preferably 30%-45% by weight, morepreferably 35%-40% by weight.

The fraction of active ingredients (component a) in the suspensionconcentrates of the invention is preferably 40%-80% by weight, inparticular 45%-60% by weight, more preferably 50%-55% by weight.

In a preferred embodiment of the invention the active ingredients(component a) are present with a minimum content of 400 g of activeingredient/I, preferably 440-820 g of active ingredient/l, morepreferably 544 g/l of active ingredient/I of the overall formulation.

Suitable active ingredients for use in the invention aredodecylguanidine or a salt, or ester thereof; or mixtures thereof.

By the term “dodecylguanidine, a salt or ester thereof” an acid salt ofdodecylguanidine of the structure (1) is meant,

wherein X represents an acid residue of a monocarboxylic acid such asacetic, propionic, capric, stearic, benzoic, and naphtoic; dicarboxylicacid such as malonic or succinic and a mineral acid such ashydrochloric, sulphuric, bisulphuric or nitric acid.

In particularly preferred embodiment of the invention, thedodecylguanidine compound is an acetate of dodecylguanidine, commonlyknown as dodine.

In an especially preferred embodiment, the fungicidal suspensionconcentrate comprises dodine as active ingredient, preferably in aconcentration of 544 g/I.

Dodine, 1-dodecylguanidinium acetate (dodecylguanidine monoacetate), isa fungicide and bactericide registered for foliar use on pome fruits,stone fruits including cherries, and nuts including walnuts.

Suspension concentrates of the invention are characterized in that 50%of the particles of the overall formulation, preferably 50% of theparticles of the active ingredients (component a), have a size of atleast 7 μm (d50>=7 μm).

More preferably 60%, even more preferably 80%, most preferably more than90%, of the particles of the overall suspension concentrate have a sizeof at least 7 μm.

In a preferred embodiment at most 2% of the particles have a particlesize of at least 75 μm (d₉₈).

It is additionally possible to add further formulation assistants tothese formulations, such as anti-freeze compounds, wetting agents,dispersing agents, antifoaming agents, preservatives, or dyes.

These formulation assistants are described for example in Chemistry andTechnology of Agrochemical Formulations, ed. D. A. Knowles, KluwerAcademic Publishers (1998) and Controlled—Release Delivery Systems forPesticides, Herbert B. Scher, Marcel Dekker, Inc. (1999).

The fraction of these formulation assistants in the suspensionconcentrates of the invention is preferably 0%-30% by weight, inparticular 2%-15% by weight, more preferably 5%-10% by weight.

In a preferred embodiment of the invention, the anti-freeze compound(component b) is selected from the list of glycols, glycerols, urea andmixtures thereof.

In a preferred embodiment, the anti-freeze compound (component b) is aglycol selected from the list of ethylene glycol, diethylene glycol,triethylene glycol, propylene glycol, dipropylene glycol,tripropyleneglycol, glycerol, and mixtures thereof.

In a particularly preferred embodiment, the anti-freeze compound ispropylene glycol.

The term “surfactant”—which includes the terms “emulsifier” and“detergent”—as used herein means a composition of matter that eitheralters surface tension when dissolved in water or an aqueous solution oralters interfacial tension between immiscible liquids or a liquid and asolid.

Surfactants suitable for purposes of the present invention are listed inMcCutcheon's Emulsifiers & Detergents, at pages 287-310 of the NorthAmerican Edition (1994), and in McCutcheon's Emulsifiers & Detergents,at pages 257-278 and 280 of the International Edition (1994), bothpublished by MC Publishing Co. (McCutcheon Division) of Glen Rock, N.J.

In this regard, suitable surfactants include, but are not limited to,alkylamine ethoxylates, acrylate graft copolymer ethoxylates, blockpolymers, carboxylated alcohol or alkylphenol ethoxylates, alcoholethoxylates, ethoxylated alkylphenols, glycol esters, polyethyleneglycols, silicone-based surfactants, and tristyrylphenol ethoxylates.

In a preferred embodiment, the surfactant is an acrylate graftcopolymer. An example of an acrylate graft copolymer is Tersperse 2500(Huntsman). This surfactant acts is easily soluble in water and acts asa dispersant.

Preferred surfactants are selected from the group consisting of wettingagents, dispersing agents and mixtures thereof.

In a preferred embodiment the wetting/dispersing agent is not an anionicwetting or dispersing agent as this may be incompatible with dodine. Ina more preferred embodiment, the dispersing/wetting agent is non-ionic.

Wetting agents serve to reduce the surface tension at the water-solidinterface and therefore increase the tendency of the water to contactthe complete surface of the active ingredient particles.

In a preferred embodiment of the invention, the wetting agent (componentc) is an ethoxylate. In a particularly preferred embodiment of theinvention, the wetting agent (component c) is selected from the list ofalkylamine ethoxylates, alkylphenol ethoxylates, alcohol ethoxylates,and tristyrylphenol ethoxylates.

In a preferred embodiment the wetting agent (component c) is analkylamine ethoxylate. Examples of alkylamine ethoxylate wetting agents(component c) are Rhodameen RAM 7 (Rhodia) or Emulson AG/NHT(Cesalpina). The advantage of this surfactant is that it acts as anemulsifier and shows a high compatibility degree with dodine.

In another preferred embodiment the wetting agent (component c) is analcohol ethoxylate. Alcohol ethoxylates are prepared from saturated orunsaturated, linear or branched aliphatic alcohols having on averagefrom 8 to 20 carbon atoms, and which contain from 5 to 25, typicallyfrom 10 to 20, ethylene oxide units per molecule. Preferred are alcoholethoxylates which contain from 12 to 18 carbon atoms in the alcoholmoiety and 10 to 20 ethylene oxide units.

Examples of alcohol ethoxylates are Brij, Volpo, Arlasolve, Atphos,Synperonic and Lubrol, Synperonic 91-6, Atplus MBA 11-7 (Uniqema).

Examples of tristyrylphenol ethoxylate wetting agents (component c) areSoprophor® 3D33 (=tristyrylphenol ethoxylated with 16 EO andphosphated), Soprophor® BSU (=tristyrylphenol ethoxylated with 16 EO),Soprophor® CY/8 (Rhodia) (=tristyrylphenol ethoxylated with 20 EO), andHoe® S3474 (=tristyrylphenol ethoxylated with 20 EO) and in the form ofthe Sapogenat® T product (Clariant), such as Sapogenate T 100(=triisobutylphenol ethoxylated with 10 EO), for example.

The fraction of surfactants in the suspension concentrates of theinvention is generally 0%-10% by weight, preferably 1%-5% by weight,more preferably 2%-4% by weight, most preferably around 3% by weight.

In a preferred embodiment of the invention, the ratio of wetting agentto particles of dodecylguanidine or a salt, or ester of thereof, isbetween 1/8 to 1/80, preferably between 1/10 to 1/25, more preferablybetween 0.04-0.06.

The term “dispersant” or “dispersing agent” as used herein connotes asurface-active agent that is added to suspending media to promoteuniform suspension or separation of solid particles, often of micrometersize.

Dispersants (components d) suitable for purposes of the presentinvention are listed in McCutcheon's Functional Materials, at pages122-142 of the North American Edition (1994), as well as in McCutcheon'sFunctional Materials, at pages 47-56 of the International Edition(1994), both published by MC Publishing Company (McCutcheon Division) ofGlen Rock, N.J.

In this regard, suitable dispersants include, but are not limited to,acrylate graft copolymers. Examples of acrylate graft copolymerdispersing agents (component d) are Tersperse 2500 (Huntsman).

The term “antifoaming agent” or “foam-control” agent or ingredient shallbe understood to mean a substance that is used to reduce foaming.Foaming may result from the presence of foam-inducing agents asproteins, gases, or nitrogenous materials. The presence of foam isgenerally undesirable because foam may interfere with processing.

Antifoaming agents are generally discussed at pages 430-447 in theKirk-Othmer Encyclopedia of Chemical Technology, third edition, volume7, published 1979 by John Wiley & Sons, Inc.

Suitable antifoaming agents (component e) for purposes of the presentinvention include but are not limited to silicone-based defoamers, fromWacker, Rhodia or Dow Corning, for example; acetylene-based defoamers,such as those from Air Products, for example, andperfluoroalkylphosphinic acid and phosphonic acids and their salts.

Preferred defoamers are those from the group of linearpolydimethylsiloxanes having an average dynamic viscosity, measured at25° C., in the range from 1000 to 800 mPa·s, usually 1200 to 6000 mPa·s,and containing silica. Silica includes polysilicic acids, meta-silicicacid, ortho-silicic acid, silica gel, silicic acid gels, kieselguhr,precipitated SiO₂, and the like.

Defoamers from the group of linear polydimethylsiloxanes contain astheir chemical backbone a compound of the formula HO—[Si(CH3)2-O-]n-H,in which the end groups are modified, by etherification for example, orare attached to the groups —Si(CH3)3. Examples of defoamers of this kindare Rhodorsil® Antifoam 416. Other suitable defoamers are Rhodorsil®1824, Antimussol 4459-2 (Clariant, Defoamer V4459 (Clariant), SE Viskand AS EM SE 39 (Wacker).

Particularly preferred are polydimethylsiloxane, wherein two methylgroups are attached to each silicon atom to form(H₃C)[SiO(CH₃)₂]_(n)Si(CH₃) and simethicone, which is a mixture ofpolydimethylsiloxane and silica.

An example of a suitable defoamer is Rhodorsil® 481 and Rhodorsil® 454(polydimethylsiloxane and silicon) from Rhodia.

An aqueous suspension concentrate according to an embodiment of theinvention may further comprise g) a thickening agent and/or h) abiocidal compound.

A suitable thickening agent (component g) is a hydroxyethylcellulose, agelling and thickening agent derived from cellulose. Especiallypreferred is hydroxyethylcellulose surface-treated with glyoxal. Asuitable thickener is, for example Natrosol® 250 HXR fromHercules-Aqualon.

Suitable preservatives (component h) are typical biocidal compounds, anexample being Promex Na20S (1,2-Benzisothiazolin-3-one) from Prom Chem,and Acticide® MBS (mixture of 1,2-benzoisothiazol-3(2H)-one and2-methyl-2H-isothiazol-3-one, biocide) from Thor.

In a preferred embodiment of the invention, the suspension concentratefurther comprises g) a thickening agent and/or h) a biocidal compound ina concentration of up to 1%, expressed by weight based on the totalweight of the composition.

In one preferred embodiment of the invention grinding continues until50% of the particles of the active ingredient, technical grade, have asize of at least 8 μm (d50≥8 μm), preferably at least 10 μm, morepreferably at least 11 μm.

Preferably in this case at least 60% of the particles of the activeingredients (component a) in the formulation have a particle size of d50of at least 7 μm, more preferably 70%, most preferably 80% of the activeingredient particles have a particle size of at least 7 μm.

In an embodiment of the invention, the median diameter of the particlesof the active ingredient is at least 10 μm, preferably at least 12 μm,more preferably at least 14 μm, most preferably around 15 μm.

In a preferred embodiment of the invention the viscosity of thesuspension concentrate is between 500 and 1.000 mPa·s (cps), preferablybetween 600 and 900 mPa·s (cps), more preferably between 700 and 800mPa·s (cps), most preferably around 750 mPa·s (cps).

Viscosity measurement systems are known to a person skilled in the art.For instance, viscosity can be measured using a Brookfield system with aspindle 2 at 20 rpm and temperature of 20° C.

In a preferred embodiment of the invention, the suspension concentrateis comprising, expressed by weight based on the total weight of thecomposition:

a) 45 to 60% of particles of dodecylguanidine or a salt, or esterthereof;

b) 1 to 5% of an anti-freeze compound,

c) 1 to 5% of a wetting agent,

d) up to 2% of a dispersing agent,

e) up to 2% of an antifoaming agent, and

f) remainder water.

In a preferred embodiment of the invention, the suspension concentratecomprises, expressed by weight based on the total weight of thecomposition:

a) 50 to 55% of particles of dodecylguanidine or a salt, or esterthereof;

b) 3% of an anti-freeze compound,

c) 3% of a wetting agent,

d) 1% of a dispersing agent,

e) 1% of an antifoaming agent,

g) 0.1% of a thickener,

h) 0.1% of a biocide, and

f) remainder water.

With the suspension concentrates of the invention it is generallypossible to achieve an equal or better biological effect for the sameapplication rate. Due to the larger particle size versus conventionalformulations, the formulation may be less toxic to humans.

Besides this the high-concentration formulation of active ingredients inthe suspension concentrates of the invention permits the associatedadvantages, such as a lower level of packaging, as a result of which thecost and complexity involved in producing, transporting, and storing issimplified and the preparation of the spray liquors used in agriculturecan be managed more effectively as a result of the smaller quantities,such as in the context of dispensing operations and stir-mixingoperations, for example.

The suspension concentrates of the invention additionally surprisinglydisplay outstanding dispersing and stabilizing properties followingfurther dilution with liquids, preferably water.

Additionally the suspension concentrates of the invention produceformulations which are stable on storage (for long periods).

The invention further provides compositions obtainable from thesuspension concentrate of the invention by dilution with liquids,preferably aqueous liquids, more preferably water.

It can be advantageous to add further active ingredients to thecompositions thus obtained, preferably active agrochemical ingredients(e.g., as tank mix partners in the form of corresponding formulations)and/or auxiliaries and additives customary for the application, examplesbeing self-emulsifying oils such as vegetable oils or liquid paraffinsand/or fertilizers. The present invention accordingly further providescompositions of this kind, preferably fungicidal compositions, which arebased on the suspension concentrates of the invention.

In a third aspect, the invention provides uses of a suspensionconcentrate according to an embodiment of the invention for thetreatment of a fungicidal disease on agricultural crops.

In a preferred embodiment, a suspension concentrate according to anembodiment of the invention is used for the treatment of scab on apples.

Apple scab, caused by the fungal pathogen Venturia inaequalis, isconsidered to be the most important single disease of apple worldwideand one of the most costly to control.

In efficacy trial the treatment of apple scab with Dodine 544 SC wascompared with Syllit® 400 SC, a commercially available productcomprising 400 g/I dodine, and for several crops Dodine 544 SC wassubstantially more efficient than Syllit® 400 SC.

In a fourth aspect, the invention provides a method for the treatment ofan agricultural crop, comprising the step of diluting an aqueoussuspension concentrate according to an embodiment of the invention, andapplying to the agricultural crop an effective amount of the dilutedaqueous suspension concentrate.

By the term “effective amount” as used herein it is meant the leastamount of the active ingredient that is required to control the fungaldisease concerned.

In a preferred embodiment, about 1.25 litres of an aqueous suspensionconcentrate according to the invention is dissolved in 400 litres ofwater to prepare a composition for the treatment of 1 ha.

In spite of the increased particle size of the active ingredient,believed to be detrimental for the biological activity of the sprayliquid, a composition according to the invention, in particular dodine544 SC (suspension concentrate comprising 544 g/I dodine), was at leastequally effective as Syllit® 400 SC (suspension concentrate comprising400 g/I dodine).

The suspension concentrates of the invention are produced in a known way(see Winnacker-Küchler, “Chemische Technologie”, volume 7, C. HanserVerlag Munich, 4^(th) ed. 1986), such as by wet grinding of thecomponents, for example, which can take place in appropriate mills, suchas in bead mills, for example (such as batch bead mills, for example,from Drais for example, or continuous bead mills, from Bachofen, forexample), or in colloid mills (such as toothed colloid mills, fromProbst+Claasen, for example).

Suspension concentrates described in the art are typically prepared bywet grinding. By the term “wet grinding” is meant in the presentinvention the milling of materials in water or other liquid.

The active ingredient in particle form is typically wet grinded untilthe active ingredient reaches a particle size having a median diameteror d₅₀ of about 3 μm. The formulation then has a viscosity of around1000 mPa·s (cps).

Unexpectedly, the suspension concentrates containing particles of anabnormally high particle size compared to suspension concentrates knownin the art of dodecylguanidine, were stable over prolonged periods oftime.

In a preferred embodiment, a suspension concentrate according to anembodiment of the invention will be stable upon storage at a temperatureof 25° C. for a period of at least 6 months, preferably 12 months, morepreferably 18 months, most preferably at least 24 months. In a preferredembodiment, a suspension concentrate of the invention has a storagestability, of at least one year. The storage stability can be measuredby techniques known to a person skilled in the art.

To obtain a fast indication of the prolonged storage stability of aproduct CIPAC method MT 46 accelerated storage test by heating can beused. Several parameters before and after heating are typically analyzedand compared to determine if the products has changed: pH (CIPAC MT75.3), pourability (CIPAC MT 148.1), suspensibility (CIPAC MT 184),spontaneity of dispersion (CIPAC MT 160), wet sieve test (CIPAC MT 185),persistent foam (CIPAC MT 47.2), particle size distribution (CIPAC MT187), low temperature stability (CIPAC MT 39.3).

A good product pourability demonstrates that the user can make use ofthe maximum amount of the preparation and that an excessive amount ofthe material does not remain in the container. A suspension concentrateof good pourability has max. 5% residue and max. 0.25% rinsed residue.In a preferred embodiment, the suspension concentrate has a pour residuebelow 4% and a rinsed residue below 0.5% as measured after storage for14 days at 54° C.+/−2° C. according to CIPAC MT 46.3.1.

In a wet sieve test the residue remaining on a sieve is determined afterdispersion to ensure no unacceptable residue remains which causes theblockage of nozzles or filters on application equipment. Good productperformance is characterized by a maximum of 2% retained on a 75 μmsieve.

Active ingredient content may be measured by analytical methods known toa person skilled in the art. Dodine content, for instance may bedetermined by a reversed-phase HPLC using a 250×4.6 mm ODS-2 column,(e.g. Inertsil 5 ODS-2, 5 μm particle size, or equivalent) with mobilephase composed of acetonitrile and water with 0.005M heptane sulfonicacid at pH 3.5 (H₃PO₄) and UV detection at 200 nm. Quantification isdone by external standardization.

In a preferred embodiment of a method of the invention, above 450 g,preferably above 500 g of dodecylguanidine or a salt or ester thereof,expressed per liter of the concentrate, were suspended.

In a preferred embodiment of a method of the invention at least 500 g/lof dodecylguanidine or a salt or ester thereof, expressed per liter ofthe concentrate, is suspended in the composition.

In a preferred embodiment of a method of the invention, the method isfurther comprising the step of adding a thickener to the suspensionconcentrate in an amount to obtain a viscosity between 500 and 1.000mPa·s (cps), preferably around 750 mPa·s (cps).

The invention is further described by the following non-limitingexamples which further illustrate the invention, and are not intendedto, nor should they be interpreted to, limit the scope of the invention.

The present invention will be now described in more details, referringto examples that are not limitative.

It is supposed that the present invention is not restricted to any formof realization described previously and that some modifications can beadded to the presented example of fabrication without reappraisal of theappended claims. For example, the present invention has been describedreferring to acetate of dodecylguanidine, but it is clear that theinvention can be applied to salts of dodecylguanidine for instance or tomixtures of acetate of dodecylguanidine with other active ingredients.

EXAMPLES Example 1: Preparation of Dodine 544 SC

Water was charged to a vessel. Formulation additives, in particularpropylene glycol (antifreezing agent), ethoxylated alkylamine (wettingagent), acrylic graft polymer (dispersing agent), silicon oil(antifoaming agent), and 1,2-benzisothiazolin-3-one (preservative) wereadded according to the recipe presented in Table 1. The grounded activeingredient was suspended in the aqueous mixture. Hydroxyethylcellulose(thickener) was added until a viscosity of about 750 mPa·s (cps) wasobtained, measured with a Brookfield system using spindle 2 at 20 rpmand 20° C. The particle size distribution of the mixture was measuredusing a particle analyzer. The data for Dodine 544 SC were as follows:mean 11.08 μm, standard deviation 9.015 μm, median 7.837 μm, variance81.27 μm², C.V. 81.3%, Mode 5.354 μm, <10%: 2.634 μm, <25%: 4.551 μm,<50%: 7.837 μm, <75% 15.22 μm, <90% 24.09 μm.

TABLE 1 Dodine 544 SC Content Ingredients (g/l at 20° C.) FunctionDodine (technical, 98% purity) 555.1 (544) Active substance (Dodine, aspure) Water 383.9 Solvent Propylene glycol 30.0 Antifreeze EthoxylatedAlkylamine 30.0 Wetting Agent Acrylic graft polymer 10.0 DispersingAgent Silicon oil 10.0 Antifoaming agent Hydroxyethylcellulose 1.0Thickener 1,2-Benzisothiazolin-3-one 1.0 Biocide Total 1021 g/l

Example 2: Storage Stability of Dodine 544 SC

An accelerated storage stability test, according to CIPAC method MT 46was performed on samples obtained from the product described inExample 1. The results obtained for a set of parameters is listed inTable 2. As it can be seen from the results, the concentrated suspensionconcentrate according to an embodiment of the invention, remainedstable.

Example 3: Efficacy Data for Dodine 544 SC

Short Description of the Experiment

Fungicides were applied with a mist blower from end of March 2010 to MidJune 2010. The set-up of the experiment was a randomised block designwith 12 treatments and four replicates. Assessments were made accordingto EPPO-guidelines PP 1/152(3) Design and analysis of efficacyevaluation trials, PP 1/135(3) Phytotoxicity assessment, PP 1/181(3)Conduct and reporting of efficacy evaluation trials including GEP, PP1/5(3) Venturia inaequalis and V. pyrina, CEB 14 Scabs of pears andapples; on shoot, fruit and leaf infections. The new fungicideformulations were compared to standards and a control treatment.

TABLE 2 Storage stability of the concentrated aqueous suspensionobtained in Example 2. Sample stored 14 Test parameter Initial sampledays at 54° C. Appearance physical state liquid liquid opacity opaqueopaque color white white pH 5.97 5.94 Viscosity (mPa · s (cps), 810 82020° C.) Persistent foaming <50 mL <50 mL (after 1 min - 1% -CIPC D- 30°C.) d50-d90 8.94-29 10.8-34.9 Wet sieve retained on 315 μm Not measuredNot measured retained on 150 μm 0.009% 0.008% retained on 40 μm 0.290%0.307% Active ingredient content % w/w 53.6 53.4 g/l 547.5 545.7

Orchard and Equipment

The experiment was conducted at trial site in Greece. The trial site isan orchard with cultivars of apple (Malus domestica, Pink lady variety).Treatments were applied with a mist blower, a ground speed of 0.18 kph.This resulted in a spray volume of 1000 I/ha.

Treatments

The following fungicides were applied:

1. untreated 2. Dodine 544 SC 0.125 l/100 l 680 g active ingredient/ha3. Syllit ® 400 SC 0.170 l/100 l 680 g active ingredient/ha

Results

The preliminary results are presented in Table 3. In this means table,means followed by the same letter do not significantly differ (P=0.05,Student-Newman-Keuls). From the results it may be concluded that theDodine 544 SC formulation controls scab on apples at least equally goodand even better than Syllit® 400 SC.

TABLE 3 Field trial results Leaf Leaf Leaf Leaf Leaf Leaf Part rate 9 1315 6 10 14 Rating Pest Pest Pest Pest Pest Pest type incidence incidenceincidence severity severity severity Treatment 1  0.00 c  0.00 e 100.00a 0.54 a 4.49 a 6.41 a 2 100.00 a 53.75 bcd  92.50 ab 0.00 b 0.46 bc2.10 b 3 100.00 a 48.75 bcd  88.75 ab 0.00 b 0.58 b 2.08 b Leaf LeafLeaf Leaf Leaf Leaf Part rate 7 11 17 8 12 16 Rating Pest Pest Pest PestPest Pest type incidence incidence incidence severity severity severityTreatment 1 51.25 a 100.00 a  0.00 c  0.00 c  0.00 d  0.00 d 2  0.00 b 46.25 bcd  7.50 bc 100.00 a 89.70 bc 66.69 bc 3  0.00 b  51.25 bcd11.25 bc 100.00 a 87.43 bc 67.24 bc

Example 4

Several dodine 600 SC formulations were prepared according to thecompositions depicted in Table 4. The average particle size d50 (μm) isplotted in function of the viscosity of the composition, as displayed inFIG. 2. From FIG. 2 it can be seen that viscosity gradually increasesfrom about 1500 mPa·s to above 3000 mPa·s for an average particle sizeof 4 and lower. Such a viscosity is undesirable as the formulationbecomes too viscous, thus difficult to handle. Preferably, the viscosityof an SC formulation is comprised between 550 mPa·s and 1050 mPa·s, morepreferably around 800 mPa·s. This value is obtained for an averageparticle size of 7 μm.

TABLE 4 Preparation of dodine 600 SC formulations g/l g/l g/l g/10 lweighed % w/w Water 303.5 303.5 303.5 3035 3037.70 29.7 Rhodorsil 1010.0 10.0 100 100.00 1.0 454 AM Tersperse 10 10.0 10.0 100 100.00 1.02500 Dodine 635 635.0 635.0 6350 6376.30 62.4 96.5% Rhodameen 60 60.060.0 600 600.10 5.9 RAM7/PPG Natrosol 1 1.0 1.0 10 / 250 HXR Promex 1.51.5 1.5 15 / Na2OS 1021.00 1021 1021 10210 10214.1 100.0

Example 5: Dodine 544 SC—Storage Stability, Pourability/Rinsability

A Dodine 544 SC formulation according to an embodiment of the inventionwas prepared. It contained around 54% w/w of dodine and 4% of anon-ionic wetting/dispersing agent.

Its physico-chemical parameters were tested according to test methodsknown to a skilled person. The results are provided in Table 5. Theparticle size distribution is provided in FIGS. 3 and 4.

From the results it can be seen that the active ingredient content ofsamples measured after an accelerated storage stability test, whereinsamples were stored for 14 days at 54° C., or after storage at ambienttemperature for 1 year, remains stable. This indicates that nodegradation has taken place.

TABLE 5 Storage stability of the concentrated aqueous suspensions ofExample 5. Sample stored 14 days at 54° C. Storage stability 1 year Testparameter Initial sample (CIPAC MT 46.3.1). (Croplife No 17) Activeingredient content % w/w 53.58 +/− 0.20 53.58 +/− 0.62 54.20 +/− 0.87g/l 551.2 +/− 2.0  551.1 +/− 6.5  557.6 +/− 8.9  Appearance (visual)physical state liquid liquid liquid opacity opaque opaque opaque colorwhite white white d50 7.940 μm 9.663 μm 7.434 μm Wet sieve test(material retained on a 75 0.076% w/w 0.241% w/w 0.060% w/w μm testsieve, CIPAC MT 185) Pourability - rinsability (CIPAC MT 148) Pourresidue 3.29% 3.52% Rinsed residue 0.12% 0.16%

From the results of the wet sieve test and pourability/rinsability testit becomes clear that although particles of above average size arepresent compared to prior art dodine formulations, stability ismaintained even up to one year. This is underlined by the values whichshow practically now change over this long period of time. As can beseen from the accelerated storage stability data, stability was notcompromised by an increase in particle size from 7.9 μm initially to 9.7μm after 14 days at 54° C.+/−2° C. in a closed glass bottle testaccording to CIPAC MT 46.3.1.

This stability of the highly concentrated dodine formulation was alsoobserved after 7 days at 0° C.+/−2° C. in a closed glass bottle testaccording to CIPAC MT 46.3.

Example 6: Dodine 600 SC—Particle Size, Viscosity, Storage Stability

Several dodine 600 SC formulations were prepared, as presented in Table6. They differed by the size of the particles of the dodine activeingredient. These were obtained using a conventional grinder. Theaverage particle size varied between 2 and 27 μm, as measured usinglaser diffraction. The viscosity of the formulations obtained wasmeasured using a Brookfield viscosity meter, a spindle 20, 20 rotationsper minute, and a temperature of 20° C.

The results of the viscosity measurements were plotted against theaverage particle size of the dodine active ingredient in theformulation, as depicted in FIG. 5. As can be seen from this figure, theviscosity was high for particles below 5 μm, in particular 1370-3350cPs. Unexpectedly, the viscosity drastically improved for higherparticle sizes. The data points depicted showed a viscosity of 420-180cPs for a particle size varied from 8.2 μm to 26.74 μm, as detailed inTable 6.

Sample fractions of the 600 SC formulations were stored for 14 days at54° C. This represents an accelerated storage stability test. Anassessment was conducted concerning their appearance to conclude on theproducts storage stability. The results are summarized in Table 7.

Upon visual inspection of the samples a liquid with a clear layer on thetop was observed. This layer varied from 1% to 38% with the d50 particlesize increasing from 3.2 μm to 26.74 μm. For the sample with lowestparticle size of 3.2 μm, no sediment was observed on the bottom of thesample recipient. For the samples of d50 between 3.5 and 19.26 μm asmall amount of sediment was observed on the bottom. However, the samplebecame homogeneous after shaking. For the sample with d50 of 26.4 μm,hard sediment was observed on the bottom which could not be homogenizedwith shaking. Claying of the particle sediment occurred.

We conclude from this experiment that for a Dodine 600 SC formulation, aformulation with a d50 particle size lower than 5 μm had a viscosityabove about 1500 cPs, which was difficult to handle. The increase of theparticle size of dodine above 5 μm led to a workable viscosity. Theformulation with a d50 particle size higher than 20 μm was not stable.Too hard sediment (caking) appeared. Sediment formation was notreversible.

Highly concentrated formulations with a dodine d50 particle size above 5μm and below 20 μm provided storage stable products with workableviscosity.

TABLE 6 Particle size and viscosity of freshly prepared dodine 600 SCformulations d50 (μm) Viscosity (cPs) 180 26.74 300 19.26 340 13.7 44010.51 420 8.2 1370 5.0 1660 3.8 1930 3.5 2500 3.1 3350 2.3

TABLE 7 Particle size and visual appearance after an accelerated storagestability test of 14 days at 54° C. d50 (μm) Appearance 26.74 Liquidwith 38% of a clear layer on the top and a hard sediment on the bottom(claying). Non-homogeneous after shaking 19.26 Liquid with 10% of aclear layer on the top and a small sediment on the bottom (claying).Homogeneous after shaking 13.7 Liquid with 5% of a clear layer on thetop and a small sediment on the bottom (claying). Homogeneous aftershaking 10.51 Liquid with 2% of a clear layer on the top and a smallsediment on the bottom (claying). Homogeneous after shaking 8.2 Liquidwith 2% of a clear layer on the top and a small sediment on the bottom(claying). Homogeneous after shaking 4.62 Liquid with 1% of a clearlayer on the top and a small sediment on the bottom (claying).Homogeneous after shaking 3.9 Liquid with 1% of a clear layer on the topand a small sediment on the bottom (claying). Homogeneous after shaking3.5 Liquid with 1% of a clear layer on the top and a small sediment onthe bottom (claying). Homogeneous after shaking 3.2 Liquid with 1% of aclear layer on the top and no sediment on the bottom (claying).

The invention claimed is:
 1. A suspension concentrate consisting of,expressed by weight based on the total weight of the composition, a) 45to 60% by weight of particles of dodine, b) 1 to 5% by weight of ananti-freeze compound, c) 1 to 5% by weight of a wetting agent, whereinthe wetting agent is selected from the group consisting of alkylamineethoxylates, acrylate graft copolymers, alkylphenol ethoxylates, alcoholethoxylates and tristyrylphenol ethoxylates, d) up to 2% by weight of adispersing agent, e) up to 2% by weight of an antifoaming agent, and f)optionally a thickening agent and/or a biocidal compound in aconcentration of up to 1% expressed by weight based on the total weightof the composition, and g) reminder water; wherein a median diameter ofthe dodine particles (d50) is 7-20 μm, wherein the suspensionconcentrate has a viscosity between 550 and 1,000 mPa·s, measured with aBrookfield viscosity meter using a spindle 2, 20 rpm and 20° C., andwherein the suspension concentrate, prior to dilution, remains stableupon storage such that the dodine particles do not settle out of thesuspension concentration for a period of at least 12 months.
 2. Thesuspension concentrate according to claim 1, consisting of expressed byweight based on the total weight of the composition: a) 50 to 55% byweight of particles of dodine, b) 3% by weight of an anti-freezecompound, c) 3% by weight of a wetting agent, d) 1% by weight of adispersing agent, e) 1% by weight of an antifoaming agent, f) 0.1% of athickener, g) 0.1% of a biocide, and h) remainder water.
 3. Thesuspension concentrate according to claim 1, wherein the anti-freezecompound is selected from the group consisting of propylene glycol,urea, glycerol, ethylene glycol, diethylene glycol, triethylene glycol,dipropylene glycol and tripropylene glycol.
 4. The suspensionconcentrate according to claim 1, wherein the anti-freeze compound ispropylene glycol.
 5. The suspension concentrate according to claim 1,wherein the antifoaming agent is a silicon oil, perfluoroalkylphosphinicacid or a salt thereof.
 6. The suspension concentrate according to claim1, wherein the dispersing agent is non-ionic.
 7. The suspensionconcentrate according to claim 1, wherein the dispersing agent is anacrylate graft copolymers.
 8. The suspension concentrate according toclaim 1, wherein the dispersing agent is an alkylamine ethoxylates. 9.The suspension concentrate according to claim 1, wherein the ratio ofwetting agent to particles is between 1:18 to 1:180.
 10. The suspensionconcentrate according to claim 1, wherein the ratio of wetting agent toparticles is between 1:10 to 1:25.
 11. A method for the treatment of afungicidal disease on an agricultural crop or ornamental plantconsisting of the step of diluting the aqueous suspension concentrationof claim 1 with an aqueous liquid and then applying an effective amountof the diluted aqueous suspension concentrate to the agricultural cropor ornamental plant.
 12. The method according to claim 11, wherein thefungicidal disease is apple scab and the agricultural crop is apples.